/*

 * Copyright (c) 1996, 2007, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package java.beans;

import java.beans.*;

/**

 * This is a support class to help build property editors.

 * <p>

 */

public class PropertyEditorSupport implements PropertyEditor {

    /**

     * Constructs a <code>PropertyEditorSupport</code> object.

     *

     * @since 1.5

     */

    public PropertyEditorSupport() {

        setSource(this);

    }

    /**

     * Constructs a <code>PropertyEditorSupport</code> object.

     *

     * @param source the source used for event firing

     * @since 1.5

     */

    public PropertyEditorSupport(Object source) {

        if (source == null) {

           throw new NullPointerException();

        }

        setSource(source);

    }

    /**

     * Returns the bean that is used as the

     * source of events. If the source has not

     * been explicitly set then this instance of

     * <code>PropertyEditorSupport</code> is returned.

     *

     * @return the source object or this instance

     * @since 1.5

     */

    public Object getSource() {

        return source;

    }

    /**

     * Sets the source bean.

     * <p>

     * The source bean is used as the source of events

     * for the property changes. This source should be used for information

     * purposes only and should not be modified by the PropertyEditor.

     *

     * @param source source object to be used for events

     * @since 1.5

     */

    public void setSource(Object source) {

        this.source = source;

    }

    /**

     * Set (or change) the object that is to be edited.

     *

     * @param value The new target object to be edited.  Note that this

     *     object should not be modified by the PropertyEditor, rather

     *     the PropertyEditor should create a new object to hold any

     *     modified value.

     */

    public void setValue(Object value) {

        this.value = value;

        firePropertyChange();

    }

    /**

     * Gets the value of the property.

     *

     * @return The value of the property.

     */

    public Object getValue() {

        return value;

    }

    //----------------------------------------------------------------------

    /**

     * Determines whether the class will honor the paintValue method.

     *

     * @return  True if the class will honor the paintValue method.

     */

    public boolean isPaintable() {

        return false;

    }

    /**

     * Paint a representation of the value into a given area of screen

     * real estate.  Note that the propertyEditor is responsible for doing

     * its own clipping so that it fits into the given rectangle.

     * <p>

     * If the PropertyEditor doesn't honor paint requests (see isPaintable)

     * this method should be a silent noop.

     *

     * @param gfx  Graphics object to paint into.

     * @param box  Rectangle within graphics object into which we should paint.

     */

    public void paintValue(java.awt.Graphics gfx, java.awt.Rectangle box) {

    }

    //----------------------------------------------------------------------

    /**

     * This method is intended for use when generating Java code to set

     * the value of the property.  It should return a fragment of Java code

     * that can be used to initialize a variable with the current property

     * value.

     * <p>

     * Example results are "2", "new Color(127,127,34)", "Color.orange", etc.

     *

     * @return A fragment of Java code representing an initializer for the

     *          current value.

     */

    public String getJavaInitializationString() {

        return "???";

    }

    //----------------------------------------------------------------------

    /**

     * Gets the property value as a string suitable for presentation

     * to a human to edit.

     *

     * @return The property value as a string suitable for presentation

     *       to a human to edit.

     * <p>   Returns null if the value can't be expressed as a string.

     * <p>   If a non-null value is returned, then the PropertyEditor should

     *       be prepared to parse that string back in setAsText().

     */

    public String getAsText() {

        return (this.value != null)

                ? this.value.toString()

                : null;

    }

    /**

     * Sets the property value by parsing a given String.  May raise

     * java.lang.IllegalArgumentException if either the String is

     * badly formatted or if this kind of property can't be expressed

     * as text.

     *

     * @param text  The string to be parsed.

     */

    public void setAsText(String text) throws java.lang.IllegalArgumentException {

        if (value instanceof String) {

            setValue(text);

            return;

        }

        throw new java.lang.IllegalArgumentException(text);

    }

    //----------------------------------------------------------------------

    /**

     * If the property value must be one of a set of known tagged values,

     * then this method should return an array of the tag values.  This can

     * be used to represent (for example) enum values.  If a PropertyEditor

     * supports tags, then it should support the use of setAsText with

     * a tag value as a way of setting the value.

     *

     * @return The tag values for this property.  May be null if this

     *   property cannot be represented as a tagged value.

     *

     */

    public String[] getTags() {

        return null;

    }

    //----------------------------------------------------------------------

    /**

     * A PropertyEditor may chose to make available a full custom Component

     * that edits its property value.  It is the responsibility of the

     * PropertyEditor to hook itself up to its editor Component itself and

     * to report property value changes by firing a PropertyChange event.

     * <P>

     * The higher-level code that calls getCustomEditor may either embed

     * the Component in some larger property sheet, or it may put it in

     * its own individual dialog, or ...

     *

     * @return A java.awt.Component that will allow a human to directly

     *      edit the current property value.  May be null if this is

     *      not supported.

     */

    public java.awt.Component getCustomEditor() {

        return null;

    }

    /**

     * Determines whether the propertyEditor can provide a custom editor.

     *

     * @return  True if the propertyEditor can provide a custom editor.

     */

    public boolean supportsCustomEditor() {

        return false;

    }

    //----------------------------------------------------------------------

    /**

     * Adds a listener for the value change.

     * When the property editor changes its value

     * it should fire a {@link PropertyChangeEvent}

     * on all registered {@link PropertyChangeListener}s,

     * specifying the {@code null} value for the property name.

     * If the source property is set,

     * it should be used as the source of the event.

     * <p>

     * The same listener object may be added more than once,

     * and will be called as many times as it is added.

     * If {@code listener} is {@code null},

     * no exception is thrown and no action is taken.

     *

     * @param listener  the {@link PropertyChangeListener} to add

     */

    public synchronized void addPropertyChangeListener(

                                PropertyChangeListener listener) {

        if (listeners == null) {

            listeners = new java.util.Vector<>();

        }

        listeners.addElement(listener);

    }

    /**

     * Removes a listener for the value change.

     * <p>

     * If the same listener was added more than once,

     * it will be notified one less time after being removed.

     * If {@code listener} is {@code null}, or was never added,

     * no exception is thrown and no action is taken.

     *

     * @param listener  the {@link PropertyChangeListener} to remove

     */

    public synchronized void removePropertyChangeListener(

                                PropertyChangeListener listener) {

        if (listeners == null) {

            return;

        }

        listeners.removeElement(listener);

    }

    /**

     * Report that we have been modified to any interested listeners.

     */

    public void firePropertyChange() {

        java.util.Vector<PropertyChangeListener> targets;

        synchronized (this) {

            if (listeners == null) {

                return;

            }

            targets = unsafeClone(listeners);

        }

        // Tell our listeners that "everything" has changed.

        PropertyChangeEvent evt = new PropertyChangeEvent(source, null, null, null);

        for (int i = 0; i < targets.size(); i++) {

            PropertyChangeListener target = targets.elementAt(i);

            target.propertyChange(evt);

        }

    }

    @SuppressWarnings("unchecked")

    private <T> java.util.Vector<T> unsafeClone(java.util.Vector<T> v) {

        return (java.util.Vector<T>)v.clone();

    }

    //----------------------------------------------------------------------

    private Object value;

    private Object source;

    private java.util.Vector<PropertyChangeListener> listeners;

}